Optical fibers are in widespread use today as the information-carrying component of communications cables because of their large bandwidth capabilities and small size. However, they are mechanically fragile, exhibiting undesirable fracture under some tensile loads and degraded light transmission under some radial compressive loads due to a phenomena known as microbending loss. Optical fibers may be subjected to tensile loading during deployment and recovery operations of optical fiber cables. Radial compressive loads are typically exerted on the optical fibers as a result of hydrostatic water pressure in submarine applications. Radial compressive loads may also result from crush and impact from trawling, anchoring, and other ship-related activities.
In many typical submarine optical fiber cables, a supporting metallic structure, called "armor," is employed to protect the fragile optical fibers from excessive tensile and radial forces. Many armor designs encompass numerous steel wires that are wound, in some instances in multiple layers, around a core carrying the optical fibers. Armored cables are therefore generally much more expensive than typical non-armored cables. With suitable armor, optical fiber cables are well-suited for many submarine applications. However, these traditional armored optical fiber cable designs have not proven to be cost effective for use in shallow-water coastal applications. While some success has been achieved with buried non-armored cable in shallow-water applications, such efforts have not proven to be completely satisfactory because non-armored cables often lack abrasion resistance and sufficient tensile strength to survive recovery operations. As a result, many shallow-water systems have been deployed using a high-percentage of expensive armored cable in order to gain the required protection from ship-related damage.